This application claims priority of German Application No. 101 00 859.7, filed Jan. 11, 2001, the complete disclosure of which is hereby incorporated by reference.
a) Field of the Invention
The invention is directed to a medical laser therapy device, particularly for use in surgery and ophthalmology.
b) Discussion of Related Art and Problems Addressed by the Invention
In scarcely any other medical discipline is the use of lasers so established as in ophthalmology, where patients have the very considerable advantage of noninvasive treatment which can usually be performed on an outpatient basis. Alternative methods are often unavailable or involve invasive procedures in the eye.
Almost all of the laser therapy devices currently used in ophthalmology for photocoagulation and photodynamic therapy (PDT) comprise a laser therapy device, an applicator and a beam control system which is usually constructed as a waveguide for optical radiation and which supplies the laser radiation generated by the laser therapy device to the applicator, through which the radiation, as therapy radiation, or the target beam or observation beam generated by another radiation source is directed into the eye to be treated.
Apart from Ar+, Kr+ or mixed-gas lasers whose operation is very cost-intensive and energy-intensive, solid-state type laser systems delivering therapeutic laser radiation of one wavelength are currently employed as radiation sources for photocoagulation and PDT. When different wavelengths of therapy radiation are required for different applications, it is generally necessary to use several laser systems or to refit existing systems in an uneconomical manner. Further, laser slit lamps, with or without special link systems, of many different manufacturers are known in the art and are commercially available. These laser slit lamps are connected via a light-conducting fiber arrangement to an external (remote) laser radiation source generating an acting beam and/or target beam. Laser slit lamps of this kind are also described in patent literature and in other literature, for example, U.S. Pat. No. 5,921,981. In this connection, combinations of a diode laser and slit lamp or an Nd:YAG laser and slit lamp are known, for example.
The usable wavelengths of laser radiation lie in the near infrared and visible spectral regions. Optical zoom systems in the link system or applicator are used for adjusting spot sizes. Pulsed operation of the acting beam sources, for example, by intensity modulation of the pump source, is also known.
The loss of radiation power occurring along the path from the radiation source through the slit lamp to the patient has turned out to be a substantial disadvantage in known laser slit lamps. In order to eliminate these disadvantages, it would be necessary to compensate for the transfer loss through higher optical and electrical source outputs.
Other disadvantages include the high number of electric connection lines between the laser radiation source and the applying system (laser slit lamp), high setup costs, and long light transfer via a sensitive light-conducting fiber to the applying system (laser slit lamp or link system).
It is the primary object of the invention to provide a medical laser therapy device which makes it possible to provide and apply laser radiation of different wavelengths for different applications in a simple construction by exchanging structural component parts and/or component groups and, accordingly, to enable an effective and careful treatment of areas in or on the eye of a patient.
According to the invention, this object is achieved by the laser therapy device described, for example, on the following page and otherwise below.
The medical laser therapy device primarily comprises the following main components: pump module with a coupling element, laser radiation source or sources, applicator and corresponding beam control system(s) which transmit(s) the laser radiation, wherein the individual main components, in turn, are constructed and positioned in different ways depending upon the application.
The laser therapy device in the embodiments comprises a controllable pump module with a suitable coupling element for a waveguide, a beam control device in the form of a waveguide for supplying the pumping radiation delivered by the pump module to the laser medium and/or to the applicator, and an applicator, possibly with a coupling element for a waveguide, for introducing a target beam and/or treatment beam into the patient""s eye which is to be treated.
A laser therapy device of the type mentioned above is characterized in that the pump module has laser diodes whose electromagnetic pumping radiation is in the spectral range from 800 nm to 815 nm, and in that an optics module which serves as a coupling element is provided which couples the pumping radiation into the waveguide, in that the beam control device is an Nd-doped waveguide laser with a double core or single core and a suitable reflecting coating of the fiber end faces, wherein the waveguide forms a laser cavity with radiation in a frequency range between 1050 nm and 1070 nm, in that the applicator is a laser slit lamp with zoom system having a device for frequency doubling which preferably comprises periodically poled nonlinear optical material, wherein this device is arranged inside or outside part of the laser cavity, and in that the applicator has a target beam device whose radiation is coupled collinearly into the beam path for the therapy radiation by a suitable beamsplitter.
For purposes of a simpler and versatile application, it is advantageous when the applicator is constructed as a head ophthalmoscope and a device for frequency doubling comprises a nonlinear optical material, known per se, this device being arrangement inside or outside the cavity. This nonlinear optical material can be a crystal.
The applicator can be constructed as a laser link with a zoom system and can comprise a device for frequency doubling which is made from nonlinear optical material or periodically poled nonlinear material, wherein this device is an internal or external part of the laser cavity.
Another constriction of the laser therapy device comprises a controllable pump module with a coupling element for a waveguide, a beam control device in the form of a waveguide for supplying the pumping radiation delivered by the pump module to the applicator, and an applicator with a coupling element for a waveguide for introducing a target beam and/or treatment beam into the patient""s eye which is to be treated. In this respect, it is advantageous when the pump module has laser diodes whose electromagnetic pumping radiation is in the spectral range from 800 nm to 815 nm, and an optics module is provided which couples the pumping radiation into the waveguide, the pump module has a target beam device whose radiation is coupled into the beam path for the therapy radiation collinearly by a suitable beamsplitter, the beam control device is an Nd-doped waveguide laser with a double core or single core and suitable reflecting coating of the fiber end faces, wherein the waveguide forms a laser cavity with radiation in a frequency range between 1050 nm and 1070 nm, the applicator is a laser slit lamp with a zoom system which has a device for frequency doubling comprising nonlinear optical material or periodically poled nonlinear optical material, the applicator has a device for power monitoring and a device for illuminating and observing the operating field.
It is further advantageous that the applicator is a head ophthalmoscope which has a device for frequency doubling preferably comprising nonlinear optical material which can also be periodically poled, wherein this device is an internal or external part of the laser cavity.
The applicator can also be a laser link which has a zoom system and a device for frequency doubling preferably comprising nonlinear optical material which can also be periodically poled, wherein this device can be an internal or external part of the laser cavity.
Another embodiment form of a laser therapy device, according to the invention, is characterized in that the pump module comprises laser diodes whose electromagnetic pumping radiation is in the spectral range from 830 nm to 850 nm, in that an optics module is provided which couples the pumping radiation of the laser diodes into the waveguide, in that the beam control device is constructed as a Pr/Yb-doped waveguide with suitable reflecting coating of the fiber end faces, so that the waveguide forms a laser cavity for radiation in the frequency range between 520 nm and 540 nm or between 630 nm and 640 nm, depending on its technical design, in that the applicator is a laser slit lamp with a zoom system, comprises a device for monitoring power and a device for illuminating and observing the operating field, and in that the applicator has a target beam device whose radiation is coupled into the beam path for the therapy radiation collinearly by a beamsplitter.
In this case also, the applicator can be constructed as a head ophthalmoscope or as a laser link with zoom system.
Another construction of a therapy device which meets the stated object of the invention is characterized in that the pump module comprises laser diodes whose electromagnetic pumping radiation is in the spectral range from 830 nm to 850 nm, and in that an optics module is provided which couples the radiation of the laser diodes into the waveguide, in that the beam control device is constructed as a Pr/Yb-doped waveguide with suitable reflecting coating of the fiber end faces, so that the waveguide forms a laser cavity for radiation in the frequency range between 520 nm and 540 nm or between 630 nm and 640 nm, depending on its technical design, in that the applicator is a laser slit lamp with a zoom system, comprises a device for monitoring power and a device for illuminating and observing the operating field, and in that the pump module comprises a target beam device whose radiation is coupled into the beam path for the pumping radiation collinearly by a beamsplitter.
In this connection, it is advantageous when the applicator is a laser slit lamp with a zoom system or a head ophthalmoscope.
The applicator can also advantageously be a laser link with zoom system.
A therapy device which also meets the above-stated object is characterized in that the pump module comprises laser diodes whose electromagnetic pumping radiation is in the spectral range from 970 nm to 980 nm, and in that an optics module is provided which couples the pumping radiation of the laser diodes into the fiber, in that the beam control device is constructed as an Er-doped waveguide with suitable reflecting coating of the waveguide end faces, so that the waveguide forms a laser cavity for radiation in the frequency range between 540 nm and 550 nm, in that the applicator is a laser slit lamp with a zoom system, in that the applicator comprises a device for monitoring power, in that the applicator comprises a device for illuminating and observing the operating field, and in that the applicator comprises a target beam device whose radiation is coupled into the beam path for the therapy radiation collinearly by a beamsplitter.
In this case, the applicator is also advantageously a head ophthalmoscope or a laser link with zoom system.
In another modification of a laser therapy device according to the invention, it is advantageous that the pump module comprises laser diodes whose electromagnetic pumping radiation is in the spectral range from 970 nm to 980 nm and that an optics module is provided which couples the pumping radiation of the laser diodes into the fiber, the beam control device is constructed as an Er-doped waveguide with suitable reflecting coating of the waveguide end faces, so that the waveguide forms a laser cavity for radiation in the frequency range between 540 nm and 550 nm, the applicator is a laser slit lamp with a zoom system, the applicator comprises a device for monitoring power and a device for illuminating and observing the operating field, and the pump module comprises a target beam device whose radiation is coupled into the beam path for the pumping radiation collinearly by a suitable beamsplitter.
In this device, also, the applicator is advantageously a laser slit lamp with zoom system. However, it can also be constructed as a head ophthalmoscope.
Further, the applicator can be a laser link with zoom system.
Another laser therapy device, constructed according to the invention, for medical applications comprises a controllable pump module with a coupling element for a waveguide, a beam control device in the form of a waveguide for supplying the pumping radiation delivered by the pump module to the applicator, and an applicator with a coupling element for the waveguide for introducing a target beam and/or treatment beam into the patient""s eye which is to be treated. The therapy device is further characterized in that the pump module has laser diodes whose electromagnetic pumping radiation is in the spectral range from 800 nm to 815 nm, and in that an optics module is provided which couples the pumping radiation into the waveguide, in that the beam control device is a non-doped waveguide, possibly with antireflection-coated end faces, so that the pumping radiation is supplied to the applicator, in that the applicator is a laser slit lamp with zoom system which comprises a microchip laser for converting the pumping radiation into radiation in the green spectral range, in that the applicator has a device for monitoring power and a device for illuminating and observing the operating field, and in that the applicator has a target beam device whose radiation is coupled into the beam path for the therapy radiation collinearly by a beamsplitter.
Accordingly, it is advantageous that the applicator is a head ophthalmoscope which comprises a microchip laser for converting the pumping radiation into radiation in the green spectral range.
The applicator can also be a laser link with a zoom system and with a microchip laser for converting the pumping radiation into radiation in the green spectral range.
According to another construction of the invention, the following characterizing features are provided:
the pump module comprises laser diodes whose electromagnetic pumping radiation is in the spectral range from 800 nm to 815 nm, and an optics module is provided which couples the pumping radiation into the waveguide; the beam control device is a non-doped waveguide, possibly with antireflection-coated end faces, so that the pumping radiation is supplied to the applicator; the applicator is a laser slit lamp with zoom system which comprises a microchip laser for converting the pumping radiation into radiation in the green spectral range; the applicator has a device for monitoring power and a device for illuminating and observing the operating field; the pump module has a target beam device whose radiation is coupled into the beam path for the pumping radiation collinearly by a suitable beamsplitter; the applicator is a laser slit lamp with zoom system which comprises a microchip laser for converting the pumping radiation into radiation in the green spectral range.
In this connection, the applicator is advantageously a head ophthalmoscope which comprises a microchip laser for converting the pumping radiation into radiation in the green spectral range.
The applicator can also be a laser link with zoom system which comprises a microchip laser for converting the pumping radiation into radiation in the green spectral range.
For purposes of a versatile, all-purpose application of the laser therapy device, it is particularly advantageous when the applicator is constructed as a handpiece for endoscopic or cyclophotocoagulation (xe2x80x9cCPCxe2x80x9d) applications to which is connected a beam control device in the form of a waveguide.
Generally, it is advantageous in all applications when the pump module optionally comprises a measuring device for calibrating internal output regulation.
The invention will be explained more fully in the following with reference to embodiment examples.